An amplifier is an electronic circuit used to increase a level or power of an input signal. A linear amplifier produces an output signal that is proportional to the input signal, but capable of delivering more power into a load. Linear amplifiers are typically used in radio frequency (RF) communications applications. In a communications system, amplifier linearity is important to minimize distortion in the output signal. Conventional amplifiers have a limited range of input levels where the output level is linearly related to the input level. When an upper level of the linear range is exceeded, the amplifiers begin to compress the output signal, resulting in distortion.
It would be desirable to implement RF amplifier linearity enhancement with a dynamically adjusted variable load.